package ideaEasyUse;

import java.util.ArrayList;
import java.util.List;

/**
 * idea的使用技巧
 */
public class Demo01 {
    public static void main(String[] args) {
        //1.var  终量定义
        int i = 123;
        String s = "123";

        //2.null notnull==nn
        ArrayList<String> objects = new ArrayList<>();
        objects.add("1");
        objects.add("2");
        objects.add("3");
        //2.1   objects.null
        if (objects == null) {

        }
        //2.2   objects.notnull
        if (objects != null) {

        }
        //2.3   objects.nn
        if (objects != null) {

        }

        //3.for fori
        for (Object object : objects) {

        }
        for (int i1 = 0; i1 < objects.size(); i1++) {

        }
        //4. sout soutv
        System.out.println(s);
        System.out.println("s = " + s);
        //5.if 条件判断
        //objects.size()>0.if
        if (objects.size()>0) {

        }
    }
}
